Moisture generation

ABSTRACT

A moisture generator including a water chamber, an air-receiving chamber surrounding the water chamber and a sparger situated at the bottom of the water chamber and communicating with the airreceiving chamber. A pressure regulator is provided for controlling the flow of compressed air into the water chamber. A heater is positioned in the water chamber for heating the water and includes a thermostat control for regulating the temperature of the water. A nozzle is provided for applying or directing warm moist air from the water chamber onto a surface to be treated.

United States Patent Inventor Rexlord W. Jones Columbus, Ohio Appl. No. 878,006 Filed Nov. 19, 1969 Patented July 27, 197] Assignec A. E. Staley Manufacturing Company Decatur, Ill. 1

MOISTURE GENERATION 10 Claims, 2 Drawing Figs.

US. Cl 222/146, 26 l/77, 239/597 Int. Cl 567d 5/62 Field of Search 222/146,

[56] References Cited UNITED STATES PATENTS 1,057,254 3/1913 McAndrews 261/77 2,340,832 2/ 1944 Damme et a1 222/146 Primary ExaminerLloyd L. King Assistant ExaminerEdwin D. Grant Attorney-Greist, Lockwood, Greenawalt & Dewey ABSTRACT: A moisture generator including a water chamber, an air-receiving chamber surrounding the water chamber and a sparger situated at the bottom of the water chamber and communicating with the air-receiving chamber. A pressure regulator is provided for controlling the flow of compressed air into the water chamber. A heater is positioned in the water chamber for heating the water and includes a thermostat control for regulating the temperature of the water. A nozzle is provided for applying or directing warm moist air from the water chamber onto a surface to be treated.

PATENTEU JUL27 ism SHEET 1 UF 2 FIGI 32 INVENTOR.

REXFORD W. JONES ATTORNEYS PAT ENTEU JUL 2 1 l9?! sum 2 nr 2 FIGZ 94 INVENTOR,

REXFORD w. JONES ATTORNEYS.

MOISTURE GENERATION drycleaning establishments. In the past, moisture has been obl 0 tained from so-called steamers which heat water above its boiling point to develop steam which is then discharged through a suitable dispensing device onto a surface to be treated. Such steamers, however, have not always been satisfactory since water droplets from condensed steam are frequently emitted from the dispensing device and these droplets are undesirable in some applications, e.g., in a drycleaning establishment where the water droplets can spot fabrics. Moreover, prior art steamers have not always provided adequate control or regulation of the amount of moisture which can be applied from the steamer, e.g., steam either is emitted constantly or is not available immediately upon demand.

In addition to steamers, atomizer and nebulizer devices have also been utilized in producing moist air. However, these devices have not always been satisfactory because of the large size of the water droplets emitted from such devices.

In view of the deficiencies incurred with prior art devices for producing moist air or steam, a general object of the present invention is the provision of a moisture generator for producing moist air at a controlled rate without water droplets.

Another object of the present invention is the provision of a moisture generator for producing a controlled flow of moisture-rich air without producing steam.

Another object of the present invention is the provision of a having a thermostat control for regulating the temperature of the water chamber between 170 and 200 F.

Another'object of the present invention is the provision of a moisture generator including a sparger for bubbling small air globules or bubbles through hot water so that a large surface area of the bubbles is exposed to the hot water to facilitate moisture saturation of the bubbles bubbled through the hot water.

Another object of the present invention is the provision of a moisture generator including a device for dispensing moistureladen air onto a surface to be treated wherein the dispensing device includes a nozzle and means for passing heated air through the nozzle to evaporate moisture which may have condensed within the nozzle and to maintain the nozzle at a temperature above room temperature to inhibit the formation of condensation within the nozzle when the moisture generator is in a standby condition.

Another object of the present invention is the provision of a moisture generator including an air-receiving chamber and a pressure regulator for regulating the volume of air flowing into the air-receiving chamber for controlling the output of moisture-laden air produced by the moisture generator.

Still another object of the present invention isthe provision of a moisture generator having a water chamber, an air-receiving compartment surrounding the water chamber and adapted to receive air at a pressure between 2 and p.s.i.g., a sparger positioned in the water chamber and connected to the airreceiving compartment, baffle means in the air-receiving compartment for circulating and directing air through the compartment to the sparger and a thermostatc controlled heater in the water chamber for maintaining the water temperature between and 200 F. 1

In one preferred embodiment of the present invention, the moisture generator includes a water chamber for receiving a quantity of water therein, an air-receiving compartment surrounding the water chamber, a heater disposed in the water chamber for maintaining the water in the chamber at a predetermined temperature, and a sparger at the bottom of the water chamber connected to the air-receiving compartment. The air-receiving compartment is positioned to receive heat from the water chamber for preheating compressed air received in the compartment as the air flows through the compartment to the sparger. Preferably, the moisture generator includes a pressure regulator for controlling the flow of air into the moisture generator and a dispensing device for dispensing the moisture-laden air from the top of the water chamber onto a surface to be treated.

The above and other objects and advantages of the present invention, and the manner of their attainment, will become more apparent from the following detailed description of the preferred embodiments of the invention taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a vertical sectional view, certain parts being shown in elevation, of a moisture generator made according to one embodiment of the present invention; and,

FIG. 2 is a vertical sectional view of a moisture generator forming another embodiment of the present invention.

Referring now to the drawings in greater detail, one embodiment of a moisture generator of the present invention is indicated generally at 10 in FIG. 1. The moisture generator 10 includes an inner water chamber or compartment 12 surrounded by an air-receiving chamber or compartment 14. The

water chamber 12 is in the form of an enclosed cylinder defined by a cylindrical sidewall 16, a top wall 17 and a bottom wall 18. The cylindrical sidewall 16 also forms an inner wall for the annular air-receiving chamber 14 with the airreceiving chamber being defined by the wall 16, a second cylindrical wall 20, spaced radially from, and concentrically with the wall 16, a top wall 21. and a bottom wall 22. To minimize heat loss from the water chamber 12 and the airreceiving chamber 14, an insulating jacket 24 is positioned around the air-receiving chamber 14 and beneath the bottom walls 18 and 22, and an insulating ring 26 is positioned above the air-receiving chamber 14. In the illustrated embodiment, the walls 20 and 22 are defined by an inner surface of the jacket 24, and the top wall 21 is defined by a lower side of the ring 26.

A water inlet 28, normally closed by a cap 30, is provided in the top wall 17 for filling the water chamber with water. A water outlet 32 normally closed by a plug 34, is provided at the bottom of the moisture generator 10 for draining water from the chamber 12. A suitable air inlet 36 is located in the insulating jacket 24 for receiving an air line connector 37 having a valve 38 for controlling the volume of air flowing into the air-receiving chamber 14 from a compressed air line 39 and for shutting off the incoming airflow to the chamber 14.

A sparger or bubbler 40, in the form of a flat ring, is located in the water chamber 12 at a point adjacent the bottom thereof and is connected to the air-receiving chamber 14 by a conduit 41. The sparger 40 is adapted to receive air from the chamber 14 for sparging same into the hot water in the chamber 12 through a plurality of small orifices 42. In this way, a plurality of small bubbles or globules of air are produced (as opposed to large bubbles) so that a large surface area of the bubbles is exposed to the hot water to facilitate saturation of the bubbles with moisture.

An electric immersion heater 43 of known type is disposed in the water chamber 12 and the water temperature is controlled by a thermostat (not shown). A control knob for setting the thermostat for a particular water temperature is indicated at 44. In this way, the water temperature can be maintained below the boiling point of water to prevent steam from forming in the water chamber 12.

A suitable flexible tubing 46 is connected at one end 48 to a moist air outlet 50 in the top wall 17 of the water chamber 12. A dispensing device in the form of a nozzle 52 is connected to the other end 54 of the flexible tubing 46. The nozzle 52 has a narrow outlet or slit 56 to facilitate application of moistureladen air from the nozzle 52 with brushlike" strokes of the nozzle 52 over the surface to be treated.

Preferably, the nozzle 52 includes a suitable two position valve or damper, e.g., a butterfly valve operated by a control knob 58. In a first or "Open" position, the valve is fully open and in a second or Throttle" position, the valve is partially open to bypass or throttle a small amount of air through the nozzle 52. The valve is placed in the "Throttle" position when the moisture generator is in a standby condition ready for intermittent use. In this position, a small amount of warm air is passed through the nozzle 52 to evaporate any water droplets that may have condensed therein and to maintain the temperature of the nozzle 52 above room temperature so that condensation of water on the inner surface of the nozzle 52 is minimized, if not altogether prevented, when the moisture generator is in a standby condition.

To promote and facilitate preheating of the air flowing through the air-receiving chamber 14 to the sparger 40, at least one spiral bafile 59 is secured to the outer surface of the cylindrical sidewall 16 for directing and circulating air in a circular path through the chamber 14 and for conducting heat from the water chamber 12 to the incoming air as the air passes by and makes contact with the spiral baffle 59. To enhance heat conduction, the wall 16 is preferably a thin walled, metal cylinder and the baffle 56, which is also metal, is welded thereto.

ln operating the moisture generator 10, the water chamber is first filled with water to a desired level and the water is heated to a temperature between 170 and 200 F. After the water has been heated to a desired operating temperature, compressed air at a pressure between 2 and 20 p.s.i.g. is admitted to the air-receiving chamber 14 where it is heated while passing through the chamber 14 to the sparger 40. The heated air is then bubbled through the heated water to pick up moisture therefrom. The two position valve is then moved to the "Open" position so that moisture-laden air can be applied or directed from the nozzle 52 onto a surface to be treated. It

will be understood that the volume and temperature of the moisture-laden air which is applied through the nozzle 52 is effectively regulated by adjusting the thermostat control knob 44 and by adjusting the control valve 38. Also, if desired, an automatic pressure regulator of known type can be used in place of the valve 38 for controlling the volume of air flowing into the chamber 14. It has been found that an adequate amount of moisture-laden air without water droplets is obtained from the moisture generator when operating at a water temperature of about l90 F. with the incoming air maintained at a pressure of about 10 p.s.i.g.

Referring now to FIG. 2 of the drawings, another embodiment oi the present invention is indicated generally at 60. The moisture generator 60 includes a water chamber 62 which is defined by a cylindrical wall 64, a bottom wall 65 and a top wall 66. Instead of an air-receiving chamber, the moisture generator 60 is provided with a coiled tubing 68 surrounding the chamber 62 and having an inlet end 69 connected to a compressed air line 70 and an outlet end 71 connected through a control valve 72 to a sparger 74 which has a plurality of small openings formed by a wire mesh and which is positioned in the water chamber 62 at a point adjacent the bottom thereof. Preferably, the tubing 68 frictionally engages the outer surface of the cylindrical wall 64 to facilitate and enhance heat transfer from the water chamber 62 to the air flowing through the tubing 68.

The water in the water chamber 62 is heated by an electric immersion heater 76 which has a thermowell 78 for receiving the rod portion of a dial thermometer 79. The water temperature is controlled by an adjustable thermostat control 80.

As shown, the water chamber 62 and the tubing 68 are enclosed in a cylindrical container 82. The diameter of the container 82 is preferably somewhat larger than the outer diameter of the water chamber 62 to provide an insulating space between the cylindrical wall of the container 82 and the water chamber 62. To minimize heat loss this insulating space is filled with an insulating material 83 such as polyurethane foam.

A nozzle 84 is connected by a suitable flexible tubing 86 to a rigid piece of conduit 88 connected to and extending from the top wall 66. Moisture-saturated air is fed through the conduit 88 and tubing 86 to the nozzle 84 and is dispensed from the nozzle 84 through a narrow slit 9() at the end of the nozzle 84. The construction of the nozzle 84 with the slit 90 allows the nozzle 84 to be used like a brush for painting" a surface to be treated with moisture-laden air.

The flow of moisture-laden air is regulated by a pressure regulator (not shown) connected to the air line 70 and by the control valve 72 connected to the end 71 of the tubing 68just prior to the point where the tubing 68 is connected to the sparger 74.

The control valve 72 is operated by a solenoid 94 and operation of the solenoid is controlled by a foot pedal switch 96. When the moisture generator 60 is in a standby condition, airflow from the tubing 68 to the sparger 74 is closed by the solenoid operated valve 72 and is directed by the valve 72 to a metal tube 98 which extends to the top of the container 82 where it is connected to a needle valve 100. The needle valve 100 is adjusted so that a small quantity of air is bypassed through a flexible tube 102 to the nozzle 84 when the moisture generator 60 is in the standby condition. The purpose of this bypass air is to evaporate the excess condensed moisture formed within the nozzle 84 during nonuse thereof when the moisture generator 60 is in a standby condition. Also, the warm bypass air has the effect of raising the temperature of the nozzle 84 above room temperature and in this way minimize, if not altogether inhibit, the condensation of moisture within the nozzle 84.

As shown, the water chamber 62 is provided with a connection 104 for filling the chamber 62 with water and for draining water therefrom. Also a sight gage 106 is provided for monitoring the water level 108 in the chamber 62 so that the water level 108 can be maintained at a level between one-half and one-third the capacity of the water chamber 62. Additionally, an on-off switch 110 is mounted on the container 82 for controlling the energization of the heater 76 and a pilot light 112 is mounted on the container 82 for indicating when the water temperature has reached the desired operating temperature.

To operate the moisture generator 60, the switch 110 is first turned on. When the pilot light 112 lights up" indicating the water in the water chamber 62 is at the desired operating temperature, the moisture generator is in standby condition ready for use. Then, while holding the nozzle 84 in position to paint" a surface with moisture-laden air, the operator depresses the foot pedal switch 96 to actuate the solenoid 94 and operate the control valve to connect the end 71 of the tubing 68 to the sparger 74. Compressed air will then be bubbled through the hot water to produce the moisture-laden air for painting" a surface to be treated with the nozzle 84.

lclaim:

l. A moisture generator for producing warm moist air to be applied onto a surface to be moistened, said moisture generator including a closed water chamber, heating means for heating water received in said chamber to a predetermined temperature below the boiling temperature of water, air-receiving means positioned to receive heat from said chamber for preheating compressed air received in said air-receiving means, and sparger means positioned in said closed chamber and connected to said air-receiving means for discharging small globules of preheated air into said water chamber, whereby said globules or air pickup moisture as said globules rise to the surface of said water in said water chamber.

water chamber is in the form of a closed cylinder having a cylindrical sidewall, a top wall and a bottom wall.

3. A moisture generator as defined in claim 1 wherein said air-receiving means is defined by said cylindrical sidewall of said water chamber, an'outer cylindrical wall radially spaced from and concentric with said cylindrical sidewall, a top wall and a bottom wall.

4. A moisture generator as defined in claim 3 in which at least one spiral baffle is situated in said air-receiving means and secured to one of said cylindrical walls, said baffle being adapted to direct air in a circular motion around said cylindrical sidewall toward said sparger means.

5. A moisture generator as defined in claim 1 including a nozzle means connected to the top of said chamber for dispensing moisture-laden air upon a surface to be moistened.

6. A moisture generator as defined in claim 5 wherein said moisture generator includes means for passing a controlled amount of heated air through said nozzle means to evaporate moisture which may have condensed within said nozzle means and to maintain said nozzle means at a temperature higher than room temperature to minimize condensation of moisture 7. A moisture generator as defined in claim 6 wherein said means for passing a controlled amount of heated air through said nozzle means includes a throttling valve for throttling a controlled amount of warm moist air through said nozzle means when said moisture generator is in said standby condition.

8. A moisture generator as defined in claim 1 wherein said heating means includes temperature control means for regulating the amount of moisture-laden air dispensed from said nozzle means by regulating the temperature of the water in said water chamber.

9. A moisture generator as defined in claim 1 including means for controlling the volume of air flowing through said air-receiving means whereby the amount of warm moist air dispensed from said nozzle means can be regulated by said control means.

10. A method for producing warm moist air comprising the steps of: introducing air at a pressure between 2 and 20 p.s.i.g. into a first compartment, preheating said air in said first compartment while passing said air through said first compartment, and then bubbling said air through a second compartment filled with water at a temperature between 170 to 220 F. 

1. A moisture generator for producing warm moist air to be applied onto a surface to be moistened, said moisture generator including a closed water chamber, heating means for heating water received in said chamber to a predetermined temperature below the boiling temperature of water, air-receiving means positioned to receive heat from said chamber for preheating compressed air received in said air-receiving means, and sparger means positioned in said closed chamber and connected to said airreceiving means for discharging small globules of preheated air into said water chamber, whereby said globules or air pickup moisture as said globules rise to the surface of said water in said water chamber.
 2. A moisture generator as defined in claim 1 wherein said water chamber is in the form of a closed cylinder having a cylindrical sidewall, a top wall and a bottom wall.
 3. A moisture generator as defined in claim 1 wherein said air-receiving means is defined by said cylindrical sidewall of said water chamber, an outer cylindrical wall radially spaced from and concentric with said cylindrical sidewall, a top wall and a bottom wall.
 4. A moisture generator as defined in claim 3 in which at least one spiral baffle is situated in said air-receiving means and secured to one of said cylindrical walls, said baffle being adapted to direct air in a circular motion around said cylindrical sidewall toward said sparger means.
 5. A moisture generator as defined in claim 1 including a nozzle means connected to the top of said chamber for dispensing moisture-laden air upon a surface to be moistened.
 6. A moisture generator as defined in claim 5 wherein said moisture generator includes means for passing a controlled amount of heated air through said nozzle means to evaporate moisture which may have condensed within said nozzle means and to maintain said nozzle means at a temperature higher than room temperature to minimize condensation of moisture within said nozzle means when said moisture generator is in a standby condition.
 7. A moisture generator as defined in claim 6 wherein said means for passing a controlled amount of heated air through said nozzle means includes a throttling valve for throttling a controlled amount of warm moist air through said nozzle means when said moisture generator is in said standby condition.
 8. A moisture generator as defined in claim 1 wherein said heating means includes temperature control means for regulating the amount of moisture-laden air dispensed from said nozzle means by regulating the temperature of the water in said water chamber.
 9. A moisture generator as defined in claim 1 including means for controlling the volume of air flowing through said air-receiving means whereby the amount of warm moist air dispensed from said nozzle means can be regulated by said control means.
 10. A method for producing warm moist aIr comprising the steps of: introducing air at a pressure between 2 and 20 p.s.i.g. into a first compartment, preheating said air in said first compartment while passing said air through said first compartment, and then bubbling said air through a second compartment filled with water at a temperature between 170* to 220* F. 